U.S. Pat. No. 3,244,248 discloses an attachment device for releasably connecting a flexible skirt to an air cushion vehicle. This attachment device comprizes a plurality of first and second elements having passages extending therethrough, the first elements being attached to rigid body structure of the vehicle so as to be in spaced relationship to each other with their passages aligned, and the second elements being attached in spaced relationship along an edge portion of flexible sheet material forming a component of the flexible skirt so that the passages are aligned with each other. The second elements on the flexible skirt component are positioned in the spaces between the first elements so that the passages in the first and second elements are aligned with each other, and a pin is passed through the passages so as to connect the first and second elements in hinged relationship to each other.
It is the practice on present air cushion vehicles using this attachment device to fasten the second elements to the flexible sheet material of the skirt by rivetting. For the material weight and thickness that is used at present in the manufacture of the skirt this method of fastening has proved adequate to transmit the operational loads acting upon the skirt into the second elements. When the skirt is worn beyond repair and is to be replaced the cost of drilling out the rivets in order to remove the second elements from the worn skirt is not justified, and the second elements are scrapped with the skirt.
With the advent of large sea-going air cushion vehicles, in the 250 tons and above class, the loads acting on the flexible skirt are considerably increased so that it is necessary to make use of stronger flexible sheet materials having higher weight per unit area. If an attachment device of the type disclosed in U.S. Pat. No. 3,244,248 is used to connect the skirt to the vehicle structure it is necessary to increase the size of the elements making up the device, and a large number of rivets, in the order of ten or more, are required to fix each second element to the flexible sheet materials. The increase in the size of the second elements is accompanied by an increase in their cost so that discarding them with a scrapped skirt or skirt part becomes economically undesirable.